Table 2 Biological roles and relative increase (multiplication factor) from baseline of growth factors derived from platelet-rich plasma (PRP) and autologous conditioned serum (ACS) technique compared with concentrations in whole blood (ABI)

	Source	Role	PRP	ACS
Platelets	Blood	Initial control of haemorrhage, release GF at injury site	3–86^–8	N/A (serum contains no platelets)
PDGF	Platelets	Stimulates cell replication, angiogenesis, mitogen for fibroblasts14	5–299 20	No difference26 29
VEGF	Platelets	Angiogenesis34	6–52.78 9	No data
TGF-β₁	Platelets	Key regulator in balance between fibrosis and myocyte regeneration4 35	3.5–278 9 20	1.326 29
FGF	Platelets	Simulates proliferation of myoblasts, angiogenesis1 8 12	"detected"9	7.526 29
EGF	Platelets	Proliferation of mesenchymal & epithelial cells, potentiation of other GFs36	38	No data
HGF	Plasma	Angiogenesis, mitogen for endothelial cells,21 anti-fibrotic10	No increase from baseline22	1.326
IGF-1	Plasma/liver	Stimulates myoblasts & fibroblasts, mediator in growth & repair of skeletal muscle35 37	No increase from baseline8 9 22 25	No difference26

EGF, epidermal growth factor; GF, growth factor; HGF, hepatocyte growth factor; IGF-1, insulin-like growth factor-1; PDGF, platelet-derived growth factor; PRP, platelet-rich plasma; TGF-β₁, transforming growth factor beta-1; VEGF, vascular endothelial growth factor.